#
# @lc app=leetcode.cn id=3 lang=python3
#
# [3] 无重复字符的最长子串
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# https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/description/
#
# algorithms
# Medium (30.10%)
# Total Accepted:    159.6K
# Total Submissions: 525.7K
# Testcase Example:  '"abcabcbb"'
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# 给定一个字符串，请你找出其中不含有重复字符的 最长子串 的长度。
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# 示例 1:
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# 输入: "abcabcbb"
# 输出: 3 
# 解释: 因为无重复字符的最长子串是 "abc"，所以其长度为 3。
# 
# 
# 示例 2:
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# 输入: "bbbbb"
# 输出: 1
# 解释: 因为无重复字符的最长子串是 "b"，所以其长度为 1。
# 
# 
# 示例 3:
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# 输入: "pwwkew"
# 输出: 3
# 解释: 因为无重复字符的最长子串是 "wke"，所以其长度为 3。
# 请注意，你的答案必须是 子串 的长度，"pwke" 是一个子序列，不是子串。
# 
# 
#
class Solution:
    def lengthOfLongestSubstring(self, s: str) -> int:
        length = len(s)
        if length == 0:
            return 0
        if length == 1:
            return 1
        pre = 0
        after = 0
        longestlength = 0 
        for i in range(1, length):
            after = i
            if s[i] in s[pre:i]:
                pre = pre + s[pre:i].index(s[i]) + 1
            longestlength = max(after-pre+1, longestlength)
        return longestlength
# if __name__ == '__main__':
#     s = Solution()
#     string = 'abcabcbb'
#     import pdb
#     pdb.set_trace()
#     print(s.lengthOfLongestSubstring(string))



    